Kinetics of Release of Water and Nutrients from Codfish (Gadus morhua L.) through a Heavy-Salting
Résumé
Through the typical 6 days heavy-salting, codfish releases 25% (w/w) of its physiological water due to the incorporation of high amounts of salt, 20% (w/w). Besides changes in water-holding capacity, major effects imparted by salt are modifications in muscle proteins conformation with subsequent denaturation and loss, and release of free amino acids.
Water is liberated from codfish according to a power-law kinetics, which describes biological reactions under molecular crowding. Proteins and amino acids are released by pseudo-first and pseudo-second order kinetics, which describe proteolysis.
Despite the loss of nutrients through salting, the nutritional value of codfish can be considered unchanged. A reduction by weight of 0.45% in muscle proteins, 1.24% aspartic acid, 1.4% glutamic acid, 2% arginine, 11% creatine, 0.2% glycine, 0.5% lysine, 0.4% methionine, 0.3% phenylalanine, 3.4% taurine and 3% tryptophan is noticed.